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A305122 G.f.: Sum_{k>=1} x^(2*k)/(1+x^(2*k)) * Product_{k>=1} (1+x^k)/(1-x^k). 5
0, 0, 1, 2, 4, 8, 16, 28, 47, 78, 126, 198, 306, 464, 694, 1024, 1490, 2146, 3061, 4322, 6052, 8408, 11592, 15872, 21592, 29192, 39242, 52468, 69788, 92376, 121716, 159664, 208569, 271372, 351732, 454228, 584546, 749720, 958472, 1221560, 1552210, 1966698 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

Convolution of A305121 and A000009.

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = A305101(n) - A305124(n).

a(n) ~ exp(sqrt(n)*Pi) * log(2) / (8*Pi*sqrt(n)).

MATHEMATICA

nmax = 50; CoefficientList[Series[Sum[x^(2*k)/(1+x^(2*k)), {k, 1, nmax}] * Product[(1+x^k)/(1-x^k), {k, 1, nmax}], {x, 0, nmax}], x]

CROSSREFS

Cf. A305102, A305101, A305104, A305105, A305124.

Cf. A116680, A305121.

Sequence in context: A057975 A260881 A089055 * A276677 A112128 A208933

Adjacent sequences:  A305119 A305120 A305121 * A305123 A305124 A305125

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, May 26 2018

STATUS

approved

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Last modified April 17 07:52 EDT 2021. Contains 343060 sequences. (Running on oeis4.)